1. Field of Invention
This invention relates generally to cold plates adapted to cool beverages before they are dispersed, and more particularly to a cold plate installable in the well of a sink in which it is covered with ice cubes, the configuration of the cold plate and the structure of the sink being such that as the ice cubes melt, the resultant water is drained and does not create a thermal barrier between the ice and the cold plate.
2. Status of Prior Art
At an outdoor or other affair in which cold carbonated beverages such as Coca Cola, 7-Up and Ginger Ale are to be served to a large number of guests, or beer, wine and juices, and where electrically-powered refrigerators are not available to cool these beverages, it is now common practice for this purpose to make use of a so-called cold plate placed in a tub and covered with ice cubes.
Embedded in the cold plate, which may be cast of aluminum or other metal having high thermal conductivity are cooling coils whose inputs are coupled by pipes to supply cylinders containing the different beverages, and whose outputs are coupled by pipes to a soda gun or other valved means to selectively dispense the beverages. These beverages are cooled as they pass through the cooling coils which are in heat-exchange relation to the ice cubes.
A pre-mix system is used when the beverages are fully constituted and in condition to be served. Thus if to be dispensed are a Cola soda, 7-Up soda and Ginger Ale, then these may be contained in 5 gallon supply cylinders into whose inputs are fed pressurized carbon dioxide drawn from a CO.sub.2 cylinder. The pressurized output of the soda cylinders are fed by separate lines to the cooling coils embedded in the cold plate.
In a post-mix system the beverages are not fully constituted but are in syrup form. Thus the supply may take the form of 5 gallon supply cylinders or plastic-lined boxes containing the syrups for the respective sodas to be dispensed. These syrups are intermingled with carbonated water obtained from a carbonator coupled to a pressurized water supply. But whether a pre-mix or a post-mix system is employed, cooling of the beverages takes place in the cold plates through whose cooling coils the beverages are caused to flow.
Of prior art interest is the Pritchett patent No. 4,678,104 (1987), which discloses a cooling system for dispensing beverages. Use is made for this purpose of a tub open at both its top and bottom, adapted to accommodate a cold plate having cooling coils cast therein. The cold plate, which has a block-like form, is covered by ice cubes; hence the beverages passing through these coils are brought to a low temperature.
However, the Pritchett arrangement suffers from a practical drawback; for as the ice cubes melt and water accumulates a barrier is formed between the planar top surface of the cold plate and the ice cubes. Since water at 32.degree. F. has poor thermal conductivity and lower BTU removal than ice, the beverages flowing through the cooling coils are not adequately cooled.
Moreover, in Pritchett, the relationship between the tub and the cold plate is not that all of the ice cubes filling the tub rest on the planar top of the cold plate and make no contact with the side of the plate. This cuts down the rate of heat transfer between the cold ice cubes and the beverages flowing through the cooling coils.
In Pritchett et al., 4,617,807 (1986), the cold plate is again in block-like form and has a planar top covered with ice cubes. But in this arrangement, the cold plate has a hole at its center to drain away liquefied ice. However, because the block has a planar top face, the drain hole does not act to quickly drain all of the liquefied ice, especially if the cold plate is somewhat tilted, as can often be the case in practice. Nor can the drain hole discharge water collected about the vertical sides of the cold plate.
Also of prior art interest is the Lents et al. patent No. 4,423,830 (1984), which shows a block-like cold plate that incorporates in its structure a water drain tube.